Patent EP0294852A2 successfully refreshed from Google Patents.
EP0294852A2
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Ferroelectric liquid crystal device
Assignee: Canon Inc
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Filing: 1988-06-13
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Granted: —
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Expires: 2008-06-13
Abstract
Abstract A ferroelectric liquid crystal device comprises a pair of opposite electrodes and a ferroelectric liquid crystal disposed between the electrodes. At least one of the opposite electrodes is coated with an insulating film having a thickness of 200 A or larger. The ferroelectric liquid crystal has a capacitance C LC (nF/cm 2 ) and a spontaneous polarization Ps (nCicm 2 ) and the insulating film has a capacitance Ci (nF/cm 2 ) satisfying the relationship of Ci(nF/cm 2 ) ≧ 2·Ps(nC/cm 2 )- C LC (nF/cm 2 ).
Inventors
- 👤 Akira Tsuboyama
- 👤 Yutaka Inaba
- 👤 Akio Yoshida
- 👤 Yukio Hanyu
- 👤 Toshiharu Uchimi
- 👤 Masataka Yamashita
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 08:47
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/06; C09K19/08; C09K19/10; C09K19/22; C09K19/12; C09K19/126; C09K19/20; C09K19/2007; C09K19/2021; C09K19/28; C09K19/30; C09K19/3001; C09K19/32; C09K19/322; C09K19/34; C09K19/3441; C09K19/42; C09K19/46; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/133345; G02F1/137; G02F1/139; G02F1/141
Claims Analysis
Total Claims: 57
Claim 1
Independent Claim
91 words
A ferroelectric liquid crystal device, comprising: a pair of opposite electrodes at least one of which is coated with an insulating film having a thickness of 200 A or larger, and a ferroelectric liquid crystal disposed between the opposite electrode; the improvement wherein said ferroelectric liquid crystal has a capacitance C LC (nF/cm 2 ) and a spontaneous polarization Ps (nC/cm 2 ), and said insulating film has a capacitance Ci (nF/cm 2 ) satisfying the relationship of Ci(nF/cm 2 ) ≧ 2·Ps(nC/cm 2 ) - C LC (nF/cm 2 ).
Claim 2
Dependent Claim
91 words
A ferroelectric liquid crystal device, comprising: a pair of opposite electrodes at least one of which is coated with an insulating film having a thickness of 200 A or larger, and a ferroelectric liquid crystal disposed between the opposite electrode; the improvement wherein said ferroelectric liquid crystal has a capacitance C LC (nF/cm 2 ) and a spontaneous polarization Ps (nC/cm 2 ), and said insulating film has a capacitance Ci (nF/cm 2 ) satisfying the relationship of Ci(nF/cm 2 ) ≧ 2·Ps(nC/cm 2 ) - C LC (nF/cm 2 ).
Claim 3
Dependent Claim
34 words
A device according to Claim 1, wherein said insulating film comprises a first film for preventing short circuit between the opposite electrodes and a second film for controlling alignment of the ferroelectric liquid crystal.
Claim 4
Dependent Claim
17 words
A device according to Claim 2, wherein said first film is formed on both the opposite electrodes.
Claim 5
Dependent Claim
19 words
A device according to Claim 2, wherein said first film is formed on only one of the opposite electrodes.
Claim 6
Dependent Claim
17 words
A device according to Claim 2, wherein said second film is formed on both the opposite electrodes.
Claim 7
Dependent Claim
19 words
A device according to Claim 2, wherein said second film is formed on only one of the opposite electrodes.
Claim 8
Dependent Claim
30 words
A device according to Claim 1, wherein the Ci, C Lc and Ps satisfy the relationship of: Ci(nF/cm 2 ) ≧ 7·Ps(nC/cm 2 ) - C LC (nF/cm 2 ).
Claim 9
Dependent Claim
16 words
A device according to Claim 1, wherein said Ps is 2 (nC/cm 2 ) or larger.
Claim 10
Dependent Claim
16 words
A device according to Claim 1, wherein said Ps is 5 (nC/cm 2 ) or larger.
Claim 11
Dependent Claim
16 words
A device according to Claim 1, wherein said Ps is 10 (nC/cm 2 ) or larger.
Claim 12
Dependent Claim
50 words
A device according to Claim 1, wherein said insulating film comprises a film of at least one insulating material selected from the group consisting of BaTi0 3 , SiO, Si0 2 , TiO, SnO 2 , Si 3 N 4 , polyimide, polyamide-imide, polyester-imide, polyamide, polyvinyl alcohol, polyester and polyethylene.
Claim 13
Dependent Claim
39 words
A device according to Claim 2, wherein said first film comprises a film of at least one insulating material selected from the group consisting of BaTiOa, SiO, SiOz, Ti0 2 , SnO 2 , Si 3 N 4 .
Claim 14
Dependent Claim
42 words
A device according to Claim 2, wherein said second film comprises a film of at least one insulating material selected from the group consisting of polyimide, polyamide-imide, polyester-imide, polyamide, polyvinyl alcohol, polyester and polyethylene, and is provided with a uniaxial orientation axis.
Claim 15
Dependent Claim
18 words
A device according to Claim 2, wherein said second film has a thickness of 500 A or smaller.
Claim 16
Dependent Claim
19 words
A device according to Claim 2, wherein said first film has a thickness of 100 A - 5000 A.
Claim 17
Dependent Claim
17 words
A device according to Claim 1, wherein said ferroelectric liquid crystal comprises a chiral smectic liquid crystal.
Claim 18
Dependent Claim
31 words
A device according to Claim 16, wherein said chiral smectic liquid crystal is disposed in a layer thin enough to release its helical structure in the absence of an electric field.
Claim 19
Dependent Claim
23 words
A device according to Claim 1, wherein said insulating film has a thickness in the range of from 500 A to 2000 Å.
Claim 20
Dependent Claim
75 words
A ferroelectric liquid crystal device, comprising: a pair of substrates each having a transparent electrode thereon, and a liquid crystal disposed between the substrates; the improvement wherein at least one of the substrates has a first silm of a material having a high dielectric constant or a ferroelectric material and a second film provided with a uniaxial orientation axis on its surface contacting the liquid crystal disposed in the order named on the transparent electrode.
Claim 21
Dependent Claim
75 words
A ferroelectric liquid crystal device, comprising: a pair of substrates each having a transparent electrode thereon, and a liquid crystal disposed between the substrates; the improvement wherein at least one of the substrates has a first silm of a material having a high dielectric constant or a ferroelectric material and a second film provided with a uniaxial orientation axis on its surface contacting the liquid crystal disposed in the order named on the transparent electrode.
Claim 22
Dependent Claim
15 words
A device according to Claim 19, wherein said liquid crystal is a ferroelectric liquid crystal.
Claim 23
Dependent Claim
17 words
A device according to Claim 20, wherein said ferroelectric liquid crystal comprises a chial smectic liquid crystal.
Claim 24
Dependent Claim
31 words
A device according to Claim 21, wherein said chiral smectic liquid crystal is disposed in a layer thin enough to release its helical structure in the absence of an electric field.
Claim 25
Dependent Claim
28 words
A device according to Claim 19, wherein said first film is formed of a material having a dielectric constant of 10 or larger as measured at 20 kHz.
Claim 26
Dependent Claim
28 words
A device according to Claim 19, wherein said first film is formed of a material having a dielectric constant of 20 or larger as measured at 20 kHz.
Claim 27
Dependent Claim
38 words
A device according to Claim 19, wherein said first film is formed of at least one compound selected from the group consisting of titanium oxide, aluminum oxide, magnesium oxide, lithium oxide, bismuth oxide, titanate compound and niobate compound.
Claim 28
Dependent Claim
20 words
A device according to Claim 19, wherein a polyorganosilane film is disposed between the first film and the second film.
Claim 29
Dependent Claim
80 words
A liquid crystal device, comprising: a pair of substrates each having a transparent electrode thereon, and a liquid crystal disposed between the substrates; the improvement wherein at least one of the substrates has a first film of a material having a high dielectric constant or a ferroelectric material and a second film of a low-resistivity dielectric material disposed in the order named on the transparent electrode, at least one of the second film being provided with a uniaxial orientation axis.
Claim 30
Dependent Claim
80 words
A liquid crystal device, comprising: a pair of substrates each having a transparent electrode thereon, and a liquid crystal disposed between the substrates; the improvement wherein at least one of the substrates has a first film of a material having a high dielectric constant or a ferroelectric material and a second film of a low-resistivity dielectric material disposed in the order named on the transparent electrode, at least one of the second film being provided with a uniaxial orientation axis.
Claim 31
Dependent Claim
23 words
A device according to Claim 27, wherein said second film comprises an organic film and said uniaxial orientation axis is provided by rubbing.
Claim 32
Dependent Claim
20 words
A device according to Claim 27, wherein said second film is formed by oblique vapor deposition of an inorganic material.
Claim 33
Dependent Claim
34 words
A device according to Claim 27, wherein said first film is formed of a material selected from the group consisting of titanium oxide, titanate compound and a mixture containing at least one of these.
Claim 34
Dependent Claim
24 words
A device according to claim 27, wherein said low-resistivity material constituting the second film has a volume resistivity of 10 10 Ω·cm or lower.
Claim 35
Dependent Claim
28 words
A device according to Claim 27, wherein said first film is formed of a material having a dielectric constant of 10 or larger as measured at 20 kHz.
Claim 36
Dependent Claim
15 words
A device according to Claim 27, wherein said liquid crystal is a ferroelectric liquid crystal.
Claim 37
Dependent Claim
97 words
A ferroelectric liquid crystal device, comprising: a pair of opposite electrodes at least one of which is coated with a primer layer and an alignment control film formed on the primer layer, and a ferroelectric liquid crystal disposed between the opposite electrodes: the improvement wherein said primer layer has a thickness d, and comprises a material having a dielectric constant E1 , and said alignment control film has a thickness d 2 and comprises a material having a dielectric constant E2 , satisfying the relationships of: d 1 > d 2 and ε 1 > E2 .
Claim 38
Dependent Claim
97 words
A ferroelectric liquid crystal device, comprising: a pair of opposite electrodes at least one of which is coated with a primer layer and an alignment control film formed on the primer layer, and a ferroelectric liquid crystal disposed between the opposite electrodes: the improvement wherein said primer layer has a thickness d, and comprises a material having a dielectric constant E1 , and said alignment control film has a thickness d 2 and comprises a material having a dielectric constant E2 , satisfying the relationships of: d 1 > d 2 and ε 1 > E2 .
Claim 39
Dependent Claim
52 words
A device according to Claim 34, wherein said primer layer comprises at least one material selected from the group consisting of silicon nitride, silicon nitride containing hydrogen, silicon carbide, silicon carbide containing hydrogen, silicon oxide, boron nitride, boron nitride containing hydrogen, cerium oxide, aluminum oxide, zirconium oxide, titanium oxide, and magnesium fluoride.
Claim 40
Dependent Claim
48 words
A device according to Claim 34, wherein said alignment control film comprises at least one material selected from the group consisting of polyvinyl alcohol, polyimide, polyamide-imide, polyester-imide, polyparaxylylene, polyester, polycarbonate, polyvinyl acetal, polyvinyl chloride, polyamide, polystyrene, polyethylene, cellulose resin, melamine resin, urea resin, acrylic resin and photoresist resin.
Claim 41
Dependent Claim
19 words
A device according to Claim 34, wherein the thickness of the alignment control film is 500 A or smaller.
Claim 42
Dependent Claim
24 words
A device according to Claim 34, wherein the dielectric constant ε 2 of the material constituting the alignment control film is 10.0 or below.
Claim 43
Dependent Claim
17 words
A device according to Claim 34, wherein said ferroelectric liquid crystal comprises a chiral smectic liquid crystal.
Claim 44
Dependent Claim
171 words
A ferroelectric liquid crystal device, comprising: a pair of opposite electrodes at least one of which is coated with a primer layer and an alignment control film formed on the primer layer, and a ferroelectric liquid crystal disposed between the opposite electrodes; the improvement wherein said primer layer has a thickness d, and comprises a material having a dielectric constant ε 1 , and said alignment control film has a thickness d 2 and comprises a material having a dielectric constant ε 2 , satisfying the relationships of: di > d 2 and ε 1 > E2 ; and said ferroelectric liquid crystal comprises at least one mesomorphic compound represented by the formula (1) below: wherein R 1 and R 2 respectively denote a branch or linear chain group capable of having a substituent, R, and R 2 being the same or different; A 1 and A 2 respectively denote a 6-membered ring-containing divalent group capable of having a substituent; and X denotes a single bond or a divalent chain group.
Claim 45
Dependent Claim
171 words
A ferroelectric liquid crystal device, comprising: a pair of opposite electrodes at least one of which is coated with a primer layer and an alignment control film formed on the primer layer, and a ferroelectric liquid crystal disposed between the opposite electrodes; the improvement wherein said primer layer has a thickness d, and comprises a material having a dielectric constant ε 1 , and said alignment control film has a thickness d 2 and comprises a material having a dielectric constant ε 2 , satisfying the relationships of: di > d 2 and ε 1 > E2 ; and said ferroelectric liquid crystal comprises at least one mesomorphic compound represented by the formula (1) below: wherein R 1 and R 2 respectively denote a branch or linear chain group capable of having a substituent, R, and R 2 being the same or different; A 1 and A 2 respectively denote a 6-membered ring-containing divalent group capable of having a substituent; and X denotes a single bond or a divalent chain group.
Claim 46
Dependent Claim
52 words
A device according to Claim 40, wherein the groups R 1 and R 2 are respectively selected from brached or linear alkyl groups capable of having a substituent, and alkoxy groups, acyl groups, acyloxy groups, alkoxycarbonyl groups and alkoxycarbonyloxy group containing a branched or linear alkyl unit capable of having a substituent.
Claim 47
Dependent Claim
31 words
A device according to Claim 40, wherein at least one of R 1 and R 2 in the formula (1) is an optically active chain group having an asymmetric carbon atom.
Claim 48
Dependent Claim
110 words
A device according to Claim 40, wherein at least one of R 1 and R 2 in the formula (1) is a group represented by the formula (2) below: wherein Y denotes a single bond, m denotes an integer of 0 - 8; n denotes 0 or 1; R 3 denotes a branched or linear alkyl group of 1 - 18 carbon atoms capable of having a substituent; or an alkoxy or alkoxycarbonyl group containing a branched or linear alkyl group of 1 - 18 carbon atoms capable of having a substituent; Z denotes methyl, a halogen, cyano or trifluoromethyl group; and denotes the location of an asymmetric carbon atom.
Claim 49
Dependent Claim
75 words
A device according to Claim 40, wherein at least one of A 1 and A 2 in the formula (1) is represented by the following formula (3): wherein p and q are respectively 0, 1 or 2; and A3 and At are respectively one of the following groups each capable of having a substituent: and 45. A device according to Claim 40, wherein X in the formula (1} is selected from single bond, -0-, -S-,
Claim 50
Dependent Claim
31 words
A device according to Claim 40, wherein said substituent of R 1 and R 2 in the formula (1) is selected from halogen atom, alkoxy group, trifluoromethyl group, and cyano group.
Claim 51
Dependent Claim
28 words
A device according to Claim 43, wherein the substituent of R 3 in the formula (2) is selected from halogen atom, alkoxy group, trifluoromethyl group, and cyano group.
Claim 52
Dependent Claim
29 words
A device according to Claim 44, wherein the substituent of A3 and Aa in the formula (3) is selected from halogen atom, alkoxy group, trifluoromethyl group, and cyano group.
Claim 53
Dependent Claim
52 words
A device according to Claim 40, wherein said primer layer comprises at least one material selected from the group consisting of silicon nitride, silicon nitride containing hydrogen, silicon carbide, silicon carbide containing hydrogen; silicon oxide, boron nitride, boron nitride containing hydrogen, cerium oxide, aluminum oxide, zirconium oxide, titanium oxide, and magnesium fluoride.
Claim 54
Dependent Claim
48 words
A device according to Claim 40, wherein said alignment control film comprises at least one material selected from the group consisting of polyvinyl alcohol, polyimide, polyamide-imide, polyester-imide, polyparaxylylene, polyester, polycarbonate, polyvinyl acetal, polyvinyl chloride, polyamide, polystyrene, polyethylene, cellulose resin, melamine resin, urea resin, acrylic resin and photoresist resin.
Claim 55
Dependent Claim
19 words
A device according to Claim 40, wherein the thickness of the alignment control film is 500 A or smaller.
Claim 56
Dependent Claim
23 words
A device according to Claim 40, wherein the dielectric constant E2 of the material constituting the alignment control film is 10.0 or below.
Claim 57
Dependent Claim
17 words
A device according to Claim 40, wherein said ferroelectric liquid crystal comprises a chiral smectic liquid crystal.
References Cited (Backward Citations)
No citation records indexed.
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